Post by ray on Apr 9, 2020 22:38:36 GMT
Kevin Dorney at the University of Colorado Boulder and his colleagues have made light that not only twists, but has a different degree of twist along the length of the beam.
They did this by shining two infrared laser pulses, each with a slightly different orbital angular momentum and a delay between them, through argon gas. The pulses overlap so the second hits the gas before the first finishes passing through.
As the beams strike the gas, their energy is absorbed and then quickly re-emitted by the argon atoms. "It's sort of like currency exchange but with light, and the argon is like the bank teller," says Dorney. The argon takes in the two infrared light beams and re-emits their light in a single pulse with a much shorter wavelength.
They did this by shining two infrared laser pulses, each with a slightly different orbital angular momentum and a delay between them, through argon gas. The pulses overlap so the second hits the gas before the first finishes passing through.
As the beams strike the gas, their energy is absorbed and then quickly re-emitted by the argon atoms. "It's sort of like currency exchange but with light, and the argon is like the bank teller," says Dorney. The argon takes in the two infrared light beams and re-emits their light in a single pulse with a much shorter wavelength.
